Unknown assailants shot and injured a senior military officer in the latest ambush near US-based Freeport McMoRan’s gold and copper mining concession in troubled Papua on Wednesday.

Freeport, in a statement to the Jakarta Globe, confirmed details of the attack, saying shots were fired at a security convoy near East Levee’s Kali Kopi area at about 11:00 a.m. local time.

“This area is not along our main mine road,” the statement said. “One security personnel sustained injuries requiring treatment. Police are on the scene and investigating.”

Freeport said it was cooperating with the investigation.

State news agency Antara identified the injured officer as Lt. Col. Viktor Deni, the chief of staff of Timika Brigade-20.

Tempo Interactive reported that Viktor suffered wounds to his right arm when he was shot about 30 kilometers from the notorious road linking Freeport’s Grasberg mining complex in Timika and Tembagapura, the site of numerous attacks. A driver and security guard working for Freeport were also hurt.

The news portal added that police officers from the elite Mobile Brigade (Brimob) who responded to the initial attack also came under fire, in what, if confirmed, would be the fourth such attack in a week, which have left six people injured.

The attack was similar to previous ambushes. On July 11, well-trained and organized attackers used what is believed to be military weaponry to kill Drew Nicholas Grant, a 29-year-old Australian project manager at Freeport.

A Brimob officer believed to be responding to the July 11 ambush was also killed or fell to his death down a ravine in a bid to escape.

A total of three people have been killed and more than a dozen injured in the attacks, including Freeport security officers Anselmus Gao and Gelke Pangkerego, who were wounded on Saturday.

On Sept. 9, Tembagapura military subdistrict chief Capt. Ronald Nainggolan escaped injury when his car was ambushed along the road, Antara reported.

Papua is home to a four-decade, low-level insurgency. Authorities blamed the Free Papua Movement — which sees Freeport as a symbol of outside rule — for the outbreak of violence. Some analysts believe the attacks stem from a rivalry between the police and the military over multimillion-dollar illegal gold mining or protection contracts for the Freeport operation.